docs: def _get_content(context, page, content_type, lang, fallback=True):
      """Helper function used by ``PlaceholderNode``."""
      if not page:
          return ''
  
      if not lang and 'lang' in context:
          lang = context.get('lang', pages_settings.PAGE_DEFAULT_LANGUAGE)
  
      page = get_page_from_string_or_id(page, lang)
  
      if not page:
          return ''
  
      content = Content.objects.get_content(page, lang, content_type, fallback)
      return content